Heat exchanger



April 22, L1941. o. HARTMANN 2,239,230v

HEAT EXCHANGER .Filed March 1, 1940 /rmnmveys l Patented Apr. 2 2, 1941Otto Hartmann, Kassel-Wilhelmshohe, Germany Application March 1, 1940,Serial No. 321,757 In Germany May 19, 1939 3 Claims.

This invention relates to an'indirectly heated heat exchanger, forinstance a steam generator or the like, the heating elements of whichare arranged within a drum in such a manner that they can be insertedinto the drum and withdrawn from the drum through the man-hole of thesame. The connection of these heating elelem by designing the heatingelementsin such a manner that an individual element does not exceed thedimension of the major axis of the manholeof the customary size so thatevery element Y, can be introduced into the drum and withdrawn from thesame through a man-hole of the usual size. Accordingly the headers,including the distribution chambers and the collecting chambers' withwhich the heating elements communicate, are subdivided in their verticaldirection, and the inner spaces of the superposed part chambers areconnected with one another by rolled socket pieces or the like. Makinguse of headers designed according to this invention makes it possible tochoose the height of the headers in such a way that the customary lengthof the major axis of the man-hole is not exceeded.

'I'he number. of heating elements so dimen- 'sioned is not limited toonly one in a vertical plane of the drum, but a plurality of suchelements may be arranged one above the other; The individual headerchambers of the superposed elements can be connected with one another bymeans of rolled sockets or joining pieces which,l after the elementshave been introduced into the drum, are inserted into the chambers androlled fast. In order to withdraw the elements from the drum therelatively short sockets or pieces are cut, whereafter the elements canbe individually withdrawn through the man-hole in spite of therestricted size of the same.

The division of the interior of the `individual headers into chambersreduces the number of .the openings through the drum wall. It is,furthermore, a particular feature of the invention that the heatingelements, owing to theirvsmall dimensions, can be assembled in a compactmanner, both with regard to their base area and their height, wherebythe interiorof the drum is provided with large heating surfaces. I

A point' worth mentioningv is that the manufacture of drums withmanholes of normal size is `simpler and cheaper than if the man-holesare to be of an exceedingly large size, aswas usual up to the presenttime in order to allow of the insertion of the heating elements. The twolastmentioned advantages also enable the use of the normal or standardsmall drums in the case of the indirect generation of steam, inconsequence whereof the respective boilers can likewise be manufacturedmore cheaply.

The invention is illustrated diagrammatically and by way of example onthe accompanying drawing on which Figure 1 is a Vertical longitudinalsection through a drum with heating elements designed according to thisinvention; Figure 2 is a horizontal longitudinal section through thesame; Figure 3 is a transverse section in the plane III--III of Fig, 1;Figure 4 shows a vertical longitudinal section through two superposedheader units including the collecting chambers, these parts being drawnto an enlarged scale relatively to Figs. 1 and 2; and Figure 5 is asection on the line V V of Fig. 4.

On the drawing, I (Figs. 1-3) denotes the drum which may be the upperdrum of a steam generator; the drum is partly lled with water to betransformed into working steam. The tubes 2 have the shape of hairpins,of which there are many arranged in vertical and in horizontal series,as appears from Figs. 1 and 2. The ends of the tubular heating elements1 are firmly connected to their respective headers, each of which iscomposed of distributing chambers@ and collecting chambers 4 (Fig. 4).In each unit, chamber 3 is separated from chamber 4 by partitions 5.There are, in the example in question, two header units arranged aboveone another and connected with one another by short tubular members 6formed, for example, by pieces of drawn tube. The upper ends of thechambers in the uppermost header units are closed by drawn metalplugs 1. The pieces of tube 6 are preferably secured in place byrolling; the tool for effecting this can be. introduced into the'upperends of chambers 3 and] prior to the insertion of the Stoppers l.

The lower header is l provided with a projec-y tion I0 which extendsoutwardly 'through the wall of the drum and contains a partition wall Ilforming a continuation of the partition wall- 5 of said unit. Betweenthis latter and the projjection I0 is a shoulder I2 located upon apacking ring I3 (Fig. 4). At the outer end of the projection I is a angeI l for connecting the headers to the respective pipes supplying theheat-carrier, or the heat transmitting and supplying agent, especiallysteam, and for discharging that agent, or the condensed steam, when itescapes from the chambers 4. 8 (Fig. 1) denotes the mst-mentioned pipesand 9 denotes the other ones. The ends of these pipes are secured to acommon ilange-like body I8 having suitable passages for establishingcommunication between -the pipes 8 and the chambers l, and between thepipes 9 and the chambers 4. The body I6 is connected with the ilangeIlby bolts I extending upwardly into this ilange and provided withcounter-nuts II, as clearly shown in Fig. 1. The bolts I5 press onto theouter surface of the drum and draw the header units against the packingring I3 by the intermediary of the shoulder I2, and the nuts I1press'the body I6 against theange Il whereby all these members are nrmiyconnected with one another and tightly sealed to one another.

The height of any one ofthe header units corresponds substantially withthe major axis of the man-hole I8 provided in one of the frontal wallsof `the drum. A plurality of the headers are arranged side by side (Fig.3) and two or more of the headers are superimposed upon each other. Iwish it, however, to be understood that I do -not limit myself tomerelyv two superposed units, as in Figs. 1 and 4, as more than two maybe arranged in the above-described manner. If the headers and tubeelements are to be removed fom the drum, the connecting pieces 6 are cutthrough, whereafter it is at once possible to withdrawv every tubebundle and the header unit to which it is attached through the man-holeI8.

From Figs. 1 and 4 it is seen that the pipes 2 of adjacent headersv arestaggered relatively to one another, as is the case also with the pipes8 and 9 with respect to the connecting bodies I6. From Figs. 1 and 2 itis seen, furthermore, that the interior of the drum is filled withheatby the connection of the same by means of the l assenso ingelements, or with Pipes 2 respectively, to the utmost degree. This isrendered possible only by the particular arrangement and combination ofthe various members constituting the tubes and header units, especiallyby the particular manner of subdividing the header units into chambers 3and l.- Separate holes for each chamber are not needed in the wall ofthe drum. As such holes would reduce the strength of the wall, a greaterwall thickness and consequently a heavier drum would result. Thesedrawbacks are obviated inthe simplest manner by the superposition of thedivided header units and tubular sockets, as described.

` I wish it to be understood that my invention is not limited to thedetails of the constructional form shown merely by way or example.Departures are possible remaining fully within the scope ofthe inventionand the annexed claims.

I claim: n

1. A heat exchanger for an indirect steam generating system comprising adrum, a manhole in one end of said drum, a plurality of header unitseach of which has its major dimension less than the major axis oi! saidmanhole and each of which is subdivided into a distributing chamber anda collecting chamber, said units i being mounted in rows transversely ofsaid drum with at least one unit superimposed upon another unit and withthe respective chambers thereof vertically aligned, separable jointsconnecting the superimposed units, and tube 'nun-l

